The present invention generally concerns an apparatus for heating a bath such as a galvanisation bath.
At the present time, processing baths such as galvanisation baths are frequently heated by a system which heats the crucible in which the bath is contained. However that method of heating the bath is fairly delicate to control. Another method of heating a galvanisation bath comprises disposing over the bath an arch structure consisting for example of brichwork, which is heated and which thus be radiation heats the bath and holds it at the appropriate temperature. Although that method of heating the bath is a more attractive proposition than the method which involves heating the crucible, it only has a relatively low level of effectiveness and it limits accessibility of the bath.
Another method of heating such a bath involves immersing therein heating elements of refractory material, in the form of pots, within which are disposed gas burners or electrical heating elements. The improvement in the level of effectiveness provided by that construction is an interesting proposition in particular when using electrical heating means. When using gas burners, the circulation of the hot gases in the pots gives rise to relatively substantial losses which reduce the effectiveness of the heating operation involving direct contact with the bath.
In addition the above-indicated heating arrangement using heating pots which are immersed in the bath suffer from the not inconsiderable disadvantage that they constitute a bulky structure which is immersed in the bath. In fact, the conductivity of the wall of refractory material of the pots limits the output power that each pot can provide. Therefore, the number of pots has to be multiplied, depending on the volume of the bath, the nature thereof and the temperature involved. Multiplying the pots in that way clutters up the bath and interferes with the positioning of various items of equipment.